Rail switch heater

ABSTRACT

An embodiment of a rail switch heating system is disclosed, including a controller comprising a processor and memory, an electrically resistive heating element coupled to the controller, the heating element configured for mounting to and heating a railroad rail, and software stored on the memory for executing the steps of: (a) automatically determining a pulse width modulated (PWM) cycle corresponding to a target energy consumption for cycling the heating element on and off; and (b) cycling the heating element on and off according to the PWM cycle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Nonprovisional applicationSer. No. 16/139,452, filed on Sep. 24, 2018, which claims the benefit ofU.S. Provisional Patent Application No. 62/571,093, filed on Oct. 11,2017. These applications are incorporated by reference herein in theirentirety.

BACKGROUND

The railroad industry, including passenger railroads, freight railroads,and other industry railroads, use rail switches to direct trains fromone track to another. Rail switches include a rail switch machineconnected to a rail switch rod to laterally move a switch rail to directa train from one track to another. A rail switch machine typicallyincludes an electric, hydraulic or pneumatic mechanism to cause theswitch rod to move the switch rail, which includes a pair of taperedrails that laterally move from one side of the track to the other.Switch machines may be remotely controlled and operated by a remoterailroad dispatching center, or they may be automatically or manuallycontrolled and operated at or near the switch point itself.

Switch rods are the conduit between the switch machine and the switchpoints. Switch rods are connected at one end to the switch machine andat the other end to the switch point(s). When the switch machine movesthe rods from one side to the other (only two positions are available)the rods will move the switch points from one side of the track to theother.

Electric heating elements convert electrical energy to heat energy. Railswitch heaters have been used to melt snow and ice on railway switchheaters and around railway switch actuation machines. Wind and coldtemperatures, or a combination of the two, are known to reduce theeffectiveness of conventional railway switch heaters, and especiallyrailway switch point heaters.

To help ensure that rail switches in remote locations function at alltimes, rail switch heaters are typically sized to raise the temperatureof rail switch machine components to a level that permits operation ofthe rail switch machines during expected worst case atmosphericconditions of extreme cold temperatures, high winds, and the like.However, the worst case atmospheric conditions seldom occur at anyparticular switch point on a railroad network, resulting in rail switchheaters that are substantially oversized for less demanding atmosphericconditions that more typically occur. This results in costly oversizedrail switch heater systems installed across the rail network, as well asexcessive daily operational expenses from generating more heat thandictated by atmospheric conditions.

There exists a need, therefore, for a solution that addresses these andother problems.

SUMMARY

Disclosed are various embodiments and aspects of an electric rail switchheating system configured to regulate the temperature of a railroadswitch rail and related switch components.

In one embodiment, a rail switch heating system of the instantdisclosure includes a controller comprising a processor and memory, anelectrically resistive heating element coupled to the controller, theheating element configured for mounting to and heating a railroad rail,a first sensor coupled to the controller, the first sensor configured todetect and/or measure a temperature of the rail to provide first inputdata to the controller, a second sensor coupled to the controller, thesecond sensor configured to detect and/or measure an air temperature ina vicinity of the rail to provide second input data to the controller,and software stored on the memory and executable by the processor forexecuting the steps of: (a) automatically determining a target energyconsumption for the heating element based on the first input data andthe second input data; (b) automatically determining a pulse widthmodulated (PWM) cycle corresponding to the target energy consumption forcycling the heating element on and off; and (c) if either the firstinput data or the second input data fall below a first minimum thresholdtemperature corresponding to the first input data or a second minimumthreshold temperature corresponding to the second input data,automatically cycling a flow of electricity on and off to the heatingelement in accordance with the PWM cycle.

The rail switch heating system may include a second electricallyresistive heating element coupled to the controller, where the secondelectrically resistive heating element may be positioned in a pan inproximity to a switch rod of a railroad switch. The rail switch heatingsystem may include a third electrically resistive heating element forpositioning on the rail in parallel to the first electrically resistiveheating element. The rail switch heating system may include a relaycoupled to the controller for closing and opening an electrical circuitto energize and de-energize the heating element according to the PWMcycle. The relay may be a solid state relay.

The controller may be configured to cease cycling the flow ofelectricity to the heating element upon the occurrence of (1) the firstinput data exceeding a first maximum threshold temperature, (2) thesecond input data exceeding a second maximum threshold temperature, or(3) the passage of a predetermined amount of time.

The rail switch heating system may include a third sensor for detectingand/or measuring one or more environmental conditions in the vicinity ofthe rail. The environmental conditions may include one of airtemperature, relative humidity, icing conditions, cloud cover, windspeed, wind direction, and barometric pressure.

The rail switch heating system may include third input data to thecontroller, where the third input data may include at least one of atime of day and a date, and wherein automatically determining the targetenergy consumption for the heating element is based on the third inputdata.

The rail switch heating system may include an antenna for receivingweather forecast data from a remote server, where automaticallydetermining the target energy consumption for the heating element isbased on the weather forecast data. The rail switch heating system mayinclude an antenna for transmitting the first input data to a remoteserver. The PWM cycle may vary from 30% to 100% corresponding to a rangeof 75 watts per foot to 250 watts per foot effective average energyconsumption for a 250 watts per foot heating element.

In another embodiment, a rail switch heating system of the instantdisclosure includes a controller comprising a processor and memory, anelectrically resistive heating element coupled to the controller, theheating element configured for mounting to and heating a railroad rail,a first sensor coupled to the controller, the first sensor configured todetect and/or measure a temperature of the rail to provide first inputdata to the controller, a second sensor coupled to the controller, thesecond sensor configured to detect and/or measure an air temperature ina vicinity of the rail to provide second input data to the controller,and software stored on the memory for executing the steps of: (a)automatically determining a pulse width modulated (PWM) cyclecorresponding to a target energy consumption for cycling the heatingelement on and off; and (b) if either the first input data or the secondinput data fall below a first minimum threshold temperaturecorresponding to the first input data or a second minimum thresholdtemperature corresponding to the second input data, automaticallycycling a flow of electricity to the heating element in accordance withthe PWM cycle.

The target energy consumption may be automatically determined based onthe first input data and the second input data. The rail switch heatingsystem may include a relay coupled to the controller for closing andopening an electrical circuit to energize and de-energize the heatingelement according to the PWM cycle. The relay may be a solid staterelay.

The controller may be configured to cease cycling the flow ofelectricity to the heating element upon the occurrence of (1) the firstinput data exceeding a first maximum threshold temperature, (2) thesecond input data exceeding a second maximum threshold temperature, or(3) the passage of a predetermined amount of time. The rail switchheating system may include an antenna for receiving weather forecastdata from a remote server, where automatically determining the targetenergy consumption for the heating element is based on weather forecastdata received by the controller. The PWM cycle may vary from 30% to 100%corresponding to a range of 75 watts per foot to 250 watts per footeffective average energy consumption for a 250 watts per foot heatingelement.

In another embodiment, a rail switch heating system of the instantdisclosure includes a controller comprising a processor and memory, anelectrically resistive heating element coupled to the controller, theheating element configured for mounting to and heating a railroad rail,and software stored on the memory for executing the steps of: (a)automatically determining a pulse width modulated (PWM) cyclecorresponding to a target energy consumption for cycling the heatingelement on and off; and (b) cycling the heating element on and offaccording to the PWM cycle.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent application file contains at least one drawing executed incolor. Copies of this patent application with color drawing(s) will beprovided by the Office upon request and payment of the necessary fee.

FIG. 1 is a schematic view of an embodiment of an electric rail switchheating system of the instant disclosure.

FIG. 2 is a top plan view of an exemplary rail switch systemincorporating a rail switch heating system of the instant disclosure.

FIG. 3 is a partially transparent, front perspective view of a portionof a rail switch heating system of the instant disclosure.

FIG. 4 is another front perspective view of a portion of a rail switchheating system of the instant disclosure.

FIG. 5 is a left elevation view of the rail switch heating system shownin FIG. 4.

FIG. 6 is a front perspective view of a portion of a rail switch heatingsystem of the instant disclosure.

FIG. 7 is a schematic view of an aspect of a rail switch heating systemof the instant disclosure.

FIG. 8 is a schematic view of another aspect of a rail switch heatingsystem of the instant disclosure.

FIG. 9 is a PWM cycle schedule corresponding to an embodiment of a railswitch heating system of the instant disclosure.

FIG. 10 is schematic view of another aspect of a rail switch heatingsystem of the instant disclosure

FIG. 11 is a schematic view of one embodiment of an aspect of a railswitch heating system of the instant disclosure.

DETAILED DESCRIPTION

Although the figures and the instant disclosure describe one or moreembodiments of a railway switch heater and related system, one ofordinary skill in the art would appreciate that the teachings of theinstant disclosure would not be limited to these embodiments. Forexample, the teachings of the instant disclosure may be applied tocontrolling the temperature or heat output of any electric heatingelement. It should be appreciated that any of the features of anembodiment discussed with reference to the figures herein may becombined with or substituted for features discussed in connection withother embodiments in this disclosure.

Remotely controlled or locally controlled rail switches allow for railtraffic in all modes of rail transportation. To effect the switchcommands from a remote dispatch system, or conduct localized railwayswitch control, the switch machine must be free of all encumbrances thatwould prevent the movement of the switch rail from one track to another.In warm atmospheric conditions, this is generally not an issue unlessdebris or foliage, for example, falls onto the track and impedes themovement of any of the switch components. By contrast, cold atmosphericconditions may result in icing and snow conditions that can hamper orinterfere with the operation of the switch machine and one or moreswitch point components.

Turning now to the figures, wherein like reference numerals refer tolike elements, there is shown one or more embodiments of a rail switchheater system 10 configured to prevent ice and predicted worst case coldatmospheric conditions from impeding the movement of railway switchmachines and related switch components while minimizing operating costsassociated with implementation and daily use of system 100.

As shown in the embodiment of FIGS. 1-4, system 10 includes controller12, one or more rail heating elements 14 connected to the controller 12,and one or more sensors 16 connected to the controller 12. In someembodiments, as shown in FIG. 2, controller 12 is positioned inproximity to a railway switch system 20 to control the operation of oneor more components of switch system 20 and/or one or more components ofrail heating elements 14. As discussed below, controller 12 may includeone or more software algorithms stored on memory and executable by aprocessor to control the operation of the one or more heating elements14.

System 10 may also include weather station 18 having one or moreatmospheric weather sensors to detect real-time atmospheric weatherconditions. For example, weather station 18 may include one or moresensors to detect and/or measure atmospheric temperature, wind speed anddirection, humidity, precipitation, and cloud cover, to name a few. Acamera 22 configured to acquire still photographs or video, includinglive video, of the scene near the physical location of the controller 12may be connected to weather station 18 and/or controller 12.

One or more antennas 24 configured to transmit and/or receive wirelessdata and/or communications may also be connected to weather station 18and/or controller 12. For example, the one or more antennas 24 may beconfigured to transmit or receive any type of wireless signals,including, for example, cellular, satellite, Bluetooth, and Wi-Fi, usingany form of wireless communications protocol and across any network. Theone or more antennas 24 may be configured, for example, to transmit to aremote location, such as a server associated with a remote railroaddispatch system, data acquired from real-time image data from camera 22,real-time weather data acquired by weather station 18, real-time sensordata from the one or more sensors 16, real-time heating element datafrom the one or more heating elements 14, and real-time position orstatus data from any component associated with the railway switch system20. Similarly, the one or more antennas 24 may be configured to receivewireless data from a remote location, such as from a server associatedwith the remote railroad dispatch system, and provide that data tocontroller 12 for disposition. Such data may include instructions tooperate one or more components of heating elements 14 and/or switchsystem 20. Alternatively, or in addition to the foregoing wirelesstransmission methods, such data may be transmitted or received by wire.Whether received wirelessly or by wire, in some embodiments, the datamay include current or forecasted weather data, which may be utilized bycontroller 12 to anticipate changing weather conditions and configure oroperate, in advance of such changing weather, one or more heatingelements 14 and/or switch system elements 20. In some embodiments,controller 12 may call upon historical weather data to automaticallypredict weather trends irrespective of, or in addition to, receivingcurrent or forecasted weather data. The historical weather data may havebeen acquired and stored by controller 12 over any interval, such asdaily, hourly, every quarter hour, or continuously. The algorithm ofcontroller 12 may anticipate the need for heat on a given switch pointcomponent and cause specific ones of the one or more heating elements 14to generate heat at an initial lower duty cycle to get ahead of changingill weather or temperature conditions and to maximize the longevity ofsystem 10 components by avoiding lengthy “on” duty cycles.

In some embodiments, railway switch system 20 includes a pair of runningrails 30, a pair of switch rails 32, and a switch machine 34 connectedto a switch rod 36. Switch rod 36 is connected to the pair of switchrails 32, and when actuated by the switch machine 34, the switch rod 36moves the switch rails 32 adjacent to a respect one of the running rails30.

Referring again to FIG. 2, the one or more sensors 16 may include anytype of contact or noncontact, electrical or nonelectrical devicecapable of detecting or measuring a temperature, including athermocouple, a resistance temperature detector (RTD), and a thermister,to name a few. The one or more sensors 16 may include one or more “cold”sensors 40 positioned on at least one of the running rails 30 and one ormore “hot” sensors 42 positioned on at least one of the switch rails 32.The one or more cold sensors 40 are configured and positioned to detectand/or measure the temperature of running rail 30 that is not affectedby any heat from the one or more heating elements 14 and to provide thatdata to controller 12. The one or more hot sensors 42 are configured andpositioned to detect and/or measure the temperature of switch rail 32 inproximity to the position of one or more heating elements 14 and toprovide that data to controller 12. In some embodiments, the one or morecold sensors 40 may be positioned approximately 2 meters away from thenearest heating element 14, and the one or more hot sensors 42 may bepositioned approximately 10 cm away from the nearest heating element 14.

The one or more heating elements 14 may be positioned on one or morerunning rails 30, on one or more switch rails 32, and/or on or inproximity to switch rod 36. In some embodiments, one or more heatingelements 14 are positioned on an inboard side of the respective rail30,32 while one or more sensors 16, such as cold sensors 40 and/or hotsensors 42, are positioned on an outboard side of the respective rail,30,32. In other embodiments, the more heating elements 14 and thesensors 16 are positioned on the same side of the rail, either on theinboard side or the outboard side of the rail.

Electrical leads associated with the one or more sensors 16 may berouted to one or more sensor boxes 28, and from there, routed tocontroller 12 (these connections in FIG. 2 are omitted for clarity).Similarly, the one or more heating elements are electrically connectedto the controller 12 via one or more relays 72 (these connections inFIG. 2 are omitted for clarity).

The one or more heating elements 14 may include a tubular heaterconfiguration comprising an electrically resistive heating element in atubular sheath. The one or more heating elements 14 may alternativelyinclude an electrically resistive heating element positioned in a cribheater, which may be positioned between railroad ties under the switchrod 36 on a mount where the electrically resistive heating element(s)are exposed and radiate heat upwardly toward the switch rod 36. The oneor more heating elements 14 may alternatively include an electricallyresistive heating element positioned in a pan heater comprising anenclosed pan that houses the electrically resistive heating element(s).

Turning to FIGS. 3-6, there is shown other elements of system 10 toprovide extreme amounts of heat when needed for extreme weatherconditions, while being energy efficient for less extreme weatherconditions, and also providing a redundant heater solution to protectagainst a single point of failure. To affix one or more heating elements14 to a rail, in some embodiments system 10 includes spaced apart springclips 50 configured to wrap underneath and around the rail andself-retainingly connect to the bottom shoulders 52 of the rail. Toreduce the ill effects of wind and contamination from debris, and tocause heat generated from the one or more heating elements 14 to reflectback to the rail rather than escape to the atmosphere, system 10 mayinclude cover panels 54 that are retained in place via one or morespaced apart clips 56, which are themselves held in place via fasteners58. At opposite ends, system 10 may include an end cap 60, which may bepositioned perpendicularly or at angle to the rail to limit intrusion ofwind behind the cover panels 54. Cover panels 54 and end caps 60 may bemade from any durable material, including sheet metal. The sheet metalmay be a form of stainless steel for corrosion protection. Theelectrical resistance wire positioned inside the tubular sheath of theone or more heating elements 14 may terminate at a terminal end 62 ofthe respective one or more heating elements 14. The terminal end mayinclude a quick-disconnect terminal connector 64 to connect a source ofelectricity to the heating element 14, which as described below, ariseswhen controller 12 causes a relay 72 to close an electrical circuit toenergize the heating element 14.

As shown in FIGS. 4-6, a pair of heating elements 14 may be positionedparallel to one another and retained in place against the rail by springclips 50. As will be discussed below, multiple heating elements 14positioned in this way provide redundancy to failure, which may beimportant in remote geographical locations, environmental safety, andoperational flexibility to economically adjust the amount of heat outputto meet a given atmospheric demand.

As shown in FIG. 7-9, to accommodate varying weather conditions, system10 may be configured to vary the wattage consumed by the one or moreheating elements 14. In this embodiment, system 10 includes a pair ofheating elements 14, each capable of consuming 300 watts per foot. Inother embodiments, system 10 includes one or more heating elements 14capable of consuming 250 watts per foot. In other embodiments, system 10includes one or more heating elements capable of consuming any desiredwattage per foot. In some embodiments, the heated length of the one ormore heating elements 14 is approximately 36 ft. For example, a pair of18 ft long, 250 watts per foot heating elements 14 positioned parallelto one another on a rail would provide the equivalent of 36 feet of a500 watts per foot heating element 14. In other embodiments, the one ormore heating elements 14 may be configured to any desired length and anywattage per foot.

In some embodiments, a target wattage of the one or more heatingelements 14, which may be based on current or predicted weatherconditions, may be achieved by averaging a pulsed duty cycle ofpower—PWM. This can be achieved by turning the one or more heatingelements 14 on and off in varying duty cycles and at a specificmodulation (frequency of the transition from on to off and from off toon). For example, a 250 watt per foot heating element 14 that is drivenby a 480 VAC supply could achieve a 125 watt effective wattage per footby using a duty cycle of 50% over a modulated frequency. Similarly, apair of 250 watt per foot heating elements 14 may be driven at 100% dutycycle to provide 500 watts per foot when needed for extreme weatherconditions. Thus, system 10 is able to vary the heat output from and theamount of energy consumed by the one or more heating elements 14 toachieve, for example, a target 100 watts per foot heater for a rainyday, and a target 200 watts per foot heater for a cold day. And if asingle heating element 14 fails, system 10 may be configured with morethan one heating element 14, which may be driven to their maximum heatoutput if needed. Thus, system 10 provides operational flexibility andredundancy, as well as time for railroad servicers to replace a failedcomponent.

As shown in FIG. 7 (and also in FIGS. 2 and 10), controller 12 may behoused in a cabinet 26 positioned in proximity to the switch point.Controller 12 may alternatively be housed in cabinet 26 positioned atsome distance from the switch point. The controller 12 may beelectrically connected to each of the heating elements 14 positioned onor near the switch point, whether along a running rail 30, a switch rail32, or in proximity to the switch rod 36. Power lines 75 and 76 connectcontroller 12 to respective ones of the heating elements 14 forindependent control of each of the heating elements 14. System 10 mayinclude one or more displays and user interfaces (including keyboard,touch screen display, mouse, etc.) mounted to or housed in cabinet 26.System 10 may also include data ports or other means for testing orconfiguring any component in the system.

The controller 12 is configured to receive various inputs andautomatically provide outputs according to the exemplary schematic shownin FIG. 8. For example, controller 12 may receive current or predictedweather data 66 from weather station 18 and/or air temperature data 68from the one or more sensors 16, and via algorithm 70 stored on memoryand executed by a processor, determine the appropriate target wattageper foot to drive the one or more heating elements 14 (referred to inFIG. 8 as the main load and the redundant load). The controller 12 mayutilize rail temperature data from the one or more sensors 16 todetermine whether a predetermined threshold low temperature has beenreached to begin to energize the one or more heating elements 14.Conversely, the controller 12 may utilize rail temperature data from theone or more sensors 16 to determine whether a predetermined highthreshold temperature to de-energize the one or more heating elements14.

The controller 12 communicates an output signal to one or more relays72. Relays 72 may comprise either or both electromechanical relays orsolid state relays (SSR's) for communicating operational commands to theone or more heating elements 14. However, SSR's provide over-voltageprotection, over-current protection, temperature and operational usagestability, and improved switch times and longevity. In addition, giventhe varying pulse width modulation (PWM) determined by the controlalgorithm of controller 12 and provided to the one or more heatingelements 14 via the one or more relays, SSR's may provide an alternativeto electro-mechanical relays to avoid premature failure in the field.That said, a suitable, high duty cycle-capable electro-mechanical relayis available from Siemens AG, part number 3RT2037-1AF00. The controller12 may include a safety circuit coupled with an algorithm to ensure thatthe atmospheric air temperature is below 50° F., for example, beforecommanding the one or more heating elements 14 to turn on. In this way,if the controller 12 is manually commanded, for example, during a testof the system, to provide a maximum wattage per foot command to the oneor more heating elements 14 and system 10 detects that the airtemperature is too warm to safely do so, then the safety circuit andsafety algorithm may either cause the controller 12 to cease the outputaltogether or may limit the duration of the output command to the one ormore heating elements 14.

Instead of automatically determining a target wattage per foot and thePWM command to achieve the automatically derived target wattage per footbased on weather data 66 and temperature data 68 inputs, in someembodiments the controller 12 may instead receive a target wattage perfoot from, for example, a remote railroad dispatching center. Thus,system 10 provides the flexibility to operate the one or more heatingelements 14 fully automatically, semi-automatically, or manually vialocal or remote data acquisition or input, and/or local or remote inputcommands to achieve a target wattage per foot of the one or more heatingelements 14.

Either automatically or manually, the controller 12 initiates the flowof electrical current by causing the relay 72 to close an electricalcircuit to feed the one or more heating elements 14 with electricity.Likewise, the controller 12 ceases the flow of electrical current bycausing the relay 72 to open the electrical circuit, therebyinterrupting the flow of electricity to the one or more heating elements14. The controller 12 may cause the relay 72 to close and open thecircuit as rapidly and as frequently as called for by a PWM model orschedule, within the physical limits of the relay 72, to achieve atarget watts per foot of the one or more heating elements 14.

FIG. 9 shows a representative PWM schedule to operate an exemplary 250watts per foot heating element 14. For example, to achieve 75 watts perfoot consumption from a single 250 watts per foot heating element 14, aPWM duty cycle of 30% is required. This is achieved by (1) providingelectrical current to the heating element 14 (thereby turning theheating element “on”) for 12 seconds, then (2) ceasing the flow ofelectricity to the heating element 14 for 28 seconds, and (3) repeatingthe on-off cycles for as long as desired, needed, or predetermined.Similarly, to achieve 100 watts per foot consumption from a single 250watts per foot heating element 14, a PWM duty cycle of 40% is required.This is achieved by (1) providing electrical current to the heatingelement 14 (thereby turning the heating element “on”) for 16 seconds,then (2) ceasing the flow of electricity to the heating element 14 for24 seconds, and (3) repeating the on-off cycles for as long as desired,needed, or predetermined. Duty cycles from 30% to 100% (full-time “on”)are shown in the schedule of FIG. 9.

For a target watts per foot that lies between two values on theschedule, the schedule may be interpolated using known mathematicalmethods to arrive at an appropriate duty cycle. For example, to obtain atarget 80 watts per foot, which lies between 75 watts per foot and 100watts per foot, the algorithm may interpolate the PWM duty cycle to be32%, which corresponds to a cycle that is 12.8 seconds on and 27.2seconds off.

FIG. 9 also shows a PWM schedule to operate an exemplary pair of 250watts per foot heating elements 14. In this embodiment, to achieve 275watts per foot consumption from a pair of 250 watts per foot heatingelement 14, a PWM duty cycle of 55% is required. This is achieved by (1)providing electrical current to the pair of heating elements 14 (therebyturning the heating elements “on”) for 22 seconds, then (2) ceasing theflow of electricity to the heating elements 14 for 18 seconds, and (3)repeating the on-off cycles for as long as desired, needed, orpredetermined. Similarly, to achieve 300 watts per foot consumption fromthe pair of 250 watts per foot heating elements 14, a PWM duty cycle of60% is required. This is achieved by (1) providing electrical current tothe heating element 14 (thereby turning the heating element “on”) for 24seconds, then (2) ceasing the flow of electricity to the heatingelements 14 for 16 seconds, and (3) repeating the on-off cycles for aslong as desired, needed, or predetermined. Any duty cycle between 55%and 100% (full-time “on”) is shown in the schedule of FIG. 9. Asdescribed above, the PWM schedule may be interpolated to achieve valuesthat lie between any PWM value listed in the schedule.

As shown in FIG. 10, controller 12 of system 10 may simultaneouslycontrol power distribution to multiple individual heating elements 14(or, for example, heating elements 14 arranged in pairs) positioned atvarious locations at a switch point, as also shown in FIG. 2. Forexample, channels 1 and 2 may route power over first and second powerlines 76 and 77 (and in some configurations over first power line 75 andvia first junction box 74) from first and second relays 72 to first andsecond heating elements 14 positioned on a running rail 30. Channels 3and 4 may route power over third and fourth power lines 76 and 77 (andin some configurations over second power line 75 and via second junctionbox 74) from third and fourth relays 72 to third and fourth heatingelements 14 positioned on a switch rail 32. Channels 5 and 6 may routepower over fifth and sixth power lines 76 and 77 (and in someconfigurations over third power line 75 and via third junction box 74)from fifth and sixth relays 72 to fifth and sixth heating elements 14positioned on or near a switch 36. A single cabinet 26 housingcontroller 12 can also include any number of relays 72 for distributingpower to a commensurate number of heating elements 14 positioned at aswitch point or at neighboring switch point(s) for controlling theheating thereof.

Controller 12 may be programmed to operate each of these heatingelements 14 with a different duty cycle. For example, controller 12 mayoperate channels 1 and 2 on different duty cycles from one another,which duty cycles may be different than the duty cycles for channels 3,4, 5, and 6, etc. Controller 12 may also operate channels 1 and 2 on thesame duty cycle. Likewise, controller 12 may operate channels 3 and 4 onthe same duty cycle, however, this duty cycle may be different than theduty cycle for Channels 1 and 2 as a pair.

In one embodiment, the cabinet 26 may include the following features:

-   -   Power supply 24 Vdc    -   UPS 24 Vdc    -   Battery 12 Vdc    -   230 Vac powersupply—POE Camera    -   Circuit Breaker/Fuse 2 Amp 3 pol.    -   RTU Complete (CPU, GSM modem, DI, Al, DO)    -   Safety transformer to weather station    -   1 each Energymeter Main Power    -   3 each Current transformers—Place in power section    -   7 each Energymeters (Turnouts impedance)    -   14 each Current transformers (Turnouts impedance)—Place in power        section    -   Safety Circuit delay timer    -   Internal thermostat to cabinet heater    -   Manual switches and push-button to Heartbeat    -   Touch Display 4,3″ (Color)

In one embodiment, the controller 12 may have the followingspecifications and/or features:

-   -   Input:    -   Main Voltage: 480 VAC, 3-phase, 60 Hz    -   Control Power Voltage: 24 VDC, Regulated, UPS        -   48 VAC, 60 Hz (Optional Weather Station)    -   Rail Temperature Sensors: 3-wire RTD, PT100, −50° C. to 50° C.    -   Converter: 4-20 mA control loop    -   Weather Station: Air temperature Sensor        -   3-wire RTD, PT100, −50° C. to 50° C.        -   Converter: 4-20 mA control loop        -   Dual Precipitation Sensors        -   Wind Speed Sensor    -   Power monitoring: Power        -   Current    -   Communication: GSM 4G/3G VPN (Optional)        -   Modbus RTU        -   Wireless 900 MHz FHSS        -   Wi-Fi        -   Fiber Optic, Ethernet, RS485    -   Camera IP Camera Event controlled    -   Output (Load):    -   Voltage: 480 VAC, Phase to Phase, 60 Hz    -   Power: Driven by customer requirements    -   Channels Main: 7 Channels of switch point and rod heaters        -   Main PWM between 25% and 100%        -   Solid State PWM control all Main channels    -   Channels Redundancy: 7 Channels of redundant switch point        heaters        -   A/B switch SCADA on each channel 100%        -   Redundant PWM between 25% and 100%        -   Solid State PWM control all Redundant channels    -   Ground Fault Detection: Ground Fault Detection between 0.1 and        1.0 AAC    -   General    -   Back Up: UPS up to 2 Hours    -   Energy Monitoring: Voltage, Current, Power (kW) and Power        Consumption (kWh)    -   Control Loop(s):—Automated control and monitoring with rail        temp. sensors        -   Advanced control with weather station and monitoring        -   Safety circuit Turn off with Airtemp. higher at 50° F.        -   Energy efficient control loop with PWM        -   Redundancy and advanced heating control with redundant            switch point heaters    -   Capability Cloud:        -   BluePoint SCADA Control & Monitoring system.        -   Incoming alarm handling        -   Outgoing alarm e-mail        -   Weather Forecast Snow warning/White frost (Optional)    -   SCADA Interface: Designed to directly interface with existing        SCADA systems (Actual interface will vary with SCADA System        design)    -   Cloud based SCADA: Cloud Based SCADA system designed to operate        seamlessly with the Blue Point Control System.        -   Data collection—Live Log        -   Access from anywhere with any device        -   Automated email alerts to key personnel        -   Weather Event Forecasting (Optional)    -   Alarm Monitoring        -   Door Open, Power Failure, Ground Fault, Element Failure            Sensors Failure, Battery Status, Manual Switches            Communication internal    -   Capability Acquisition        -   RTU record every 5 minutes to internal log in RTU        -   Server download every hour all RTU log data in SAN SQL DB        -   Logs presentation in SCADA        -   Export logs in Excel sheet by e-mail

Turning now to FIG. 11 there is shown another embodiment for connectingand powering the one or more heating elements 14 of system 10 tocontroller 12. As shown in this embodiment, controller 12, which may bepositioned some distance away from the rails 30,32 or switch rod 36 tobe heated, comprises one or more relays 72, each connected to a junctionbox 74 by a single, controller-modulated power line 75. Junction box 74,which may be positioned in closer proximity to a rail 30,32 or switchrod 36 to be heated than controller 12, may be configured to communicatethe modulated power feed over each power line 76 and 77 (representing amain power line for driving a first heating element 14 and a second orredundant power line for driving a second heating element 14) that areconnected to respective heating elements 14, which are identified, forexample, as main and redundant heating loads in FIG. 8.

In one possible mode of operation, either automatically or manually asdescribed above, controller 12 may initiate the flow of electricalcurrent by causing the relay 72 to close an electrical circuit and feedheating elements 14 with electricity via power lines 75,76,77 and viajunction box 74. To distribute power to one or both of power lines76,77, junction box 74 may include a fuse or circuit breaker to ensurethat failure of one of the heating elements 14 will not cause the otherheating element 14 to fail. The controller 12 may cease the flow ofelectrical current by causing the relay 72 to open the electricalcircuit, thereby interrupting the flow of electricity to the one or moreheating elements 14. The controller 12 may cause the relay 72 to closeand open the circuit as rapidly and as frequently as called for by a PWMmodel or schedule, within the physical limits of the relay 72, toachieve a target watts per foot of the one or more heating elements 14.Thus, in this configuration, controller 12 can modulate the power overpower line 75, and then junction box 74 can communicate the modulatedpower over power lines 76 and 77.

This arrangement enables easy retrofitting of existing railway heatingsystems that already have a single power line connecting a power sourceto a single rail heating element 14. It does this by avoiding the time,expense, and risk of trenching alongside the existing power line to layan additional power line to power a second heating element 14 that isplaced adjacent to an existing heating element 14 to arrive at theconfiguration shown in FIGS. 4-5, for example. This arrangement alsoresults in a significant cost savings to retrofit existing rail systemsbecause only minimal trenching from the junction box 74 to connect powerline 76 to a first or main heating element 14 and to connect power line77 to a second or redundant heating element 14 is required given therelative proximity of the junction box 74 (compared to the controller12) to the rail 30,32 or switch rod 36 to be heated.

By contrast, the arrangement shown in FIG. 7, for example, with twopower lines 76,77 directly connecting controller 12 to the pair ofheating elements 14 may be easily implemented in new rail constructionsettings where a single trench can be dug to receive the pair of powerlines 76,77 between the controller 12 and the rails 30,32 or switch rod36 to be heated.

While specific embodiments have been described in detail, it will beappreciated by those skilled in the art that various modifications andalternatives to those details could be developed in light of the overallteachings of the disclosure. Accordingly, the disclosure herein is meantto be illustrative only and not limiting as to its scope and should begiven the full breadth of the appended claims and any equivalentsthereof.

1. A rail switch heating system, comprising: a controller comprising aprocessor and memory; an electrically resistive heating element coupledto the controller, the heating element configured for mounting to andheating a railroad rail; a first sensor coupled to the controller toprovide first input data to the controller, the first sensor configuredto detect and/or measure a first temperature of the rail at a locationof the rail that is unaffected by temperature induced by the heatingelement; a second sensor coupled to the controller to provide secondinput data to the controller, the second sensor configured to detectand/or measure a second temperature of the rail at a location of therail that is affected by temperature induced by the heating element; andsoftware stored on the memory and executable by the processor forexecuting the steps of: automatically determining a target energyconsumption for the heating element based on the first input data andthe second input data; automatically determining a pulse width modulated(PWM) cycle corresponding to the target energy consumption for cyclingthe heating element on and off; and if the first input datacorresponding to the first temperature of the rail falls below a minimumthreshold temperature and if the second input data corresponding to thesecond temperature of the rail does not exceed a maximum thresholdtemperature, automatically cycling a flow of electricity on and off tothe heating element in accordance with the PWM cycle.
 2. The rail switchheating system of claim 1, including a second electrically resistiveheating element coupled to the controller, the second electricallyresistive heating element positioned in a pan in proximity to a switchrod of a railroad switch.
 3. The rail switch heating system of claim 1,including a second electrically resistive heating element positioned onthe rail and parallel to the electrically resistive heating element. 4.The rail switch heating system of claim 1, including a relay coupled tothe controller for closing and opening an electrical circuit to energizeand de-energize the heating element according to the PWM cycle.
 5. Therail switch heating system of claim 4, wherein the relay is a solidstate relay.
 6. The rail switch heating system of claim 1, wherein thecontroller is configured to cease cycling the flow of electricity to theheating element upon occurrence of (1) the second input data exceedingthe maximum threshold temperature, or (2) passage of a predeterminedamount of time.
 7. The rail switch heating system of claim 1, includinga third sensor for detecting and/or measuring one or more environmentalconditions in the vicinity of the rail.
 8. The rail switch heatingsystem of claim 7, wherein the one or more environmental conditionsinclude at least one of air temperature, relative humidity, icingconditions, cloud cover, wind speed, wind direction, and barometricpressure.
 9. The rail switch heating system of claim 1, including thirdinput data to the controller, the third input data including at leastone of a time of day and a date, wherein automatically determining thetarget energy consumption for the heating element is based on the thirdinput data.
 10. The rail switch heating system of claim 1, including anantenna for receiving weather forecast data from a remote server,wherein automatically determining the target energy consumption for theheating element is based on the weather forecast data.
 11. The railswitch heating system of claim 1, including an antenna for transmittingthe first input data to a remote server.
 12. The rail switch heatingsystem of claim 1, wherein the PWM cycle varies from 30% to 100%corresponding to a range of 75 watts per foot to 250 watts per footeffective average energy consumption for a 250 watts per foot heatingelement.
 13. A rail switch heating system, comprising: a controllercomprising a processor and memory; an electrically resistive heatingelement coupled to the controller, the heating element configured formounting to and heating a railroad rail; a first sensor coupled to thecontroller to provide first input data to the controller, the firstsensor configured to detect and/or measure a first temperature of therail at a location of the rail that is unaffected by temperature inducedby the heating element; a second sensor coupled to the controller toprovide second input data to the controller, the second sensorconfigured to detect and/or measure a second temperature of the rail ata location of the rail that is affected by temperature induced by theheating element; and software stored on the memory for executing thesteps of: automatically determining a pulse width modulated (PWM) cyclecorresponding to a target energy consumption for cycling the heatingelement on and off; and if the first input data corresponding to thefirst temperature of the rail falls below a minimum thresholdtemperature and if the second input data corresponding to the secondtemperature of the rail does not exceed a maximum threshold temperature,automatically cycling a flow of electricity on and off to the heatingelement in accordance with the PWM cycle.
 14. The rail switch heatingsystem of claim 13, wherein the target energy consumption isautomatically determined based on the first input data and the secondinput data.
 15. The rail switch heating system of claim 13, including arelay coupled to the controller for closing and opening an electricalcircuit to energize and de-energize the heating element according to thePWM cycle.
 16. The rail switch heating system of claim 15, wherein therelay is a solid state relay.
 17. The rail switch heating system ofclaim 13, wherein the controller is configured to cease cycling the flowof electricity to the heating element upon occurrence of (1) the secondinput data exceeding the maximum threshold temperature, or (2) passageof a predetermined amount of time.
 18. The rail switch heating system ofclaim 13, including an antenna for receiving weather forecast data froma remote server, wherein automatically determining the target energyconsumption for the heating element is based on the weather forecastdata received by the controller.
 19. The rail switch heating system ofclaim 13, wherein the PWM cycle varies from 30% to 100% corresponding toa range of 75 watts per foot to 250 watts per foot effective averageenergy consumption for a 250 watts per foot heating element.
 20. A railswitch heating system, comprising: a controller comprising a processorand memory; an electrically resistive heating element coupled to thecontroller, the heating element configured for mounting to and heating arailroad rail; a first sensor coupled to the controller to provide firstinput data to the controller, the first sensor configured to detectand/or measure a first temperature of the rail at a location of the railthat is unaffected by temperature induced by the heating element; asecond sensor coupled to the controller to provide second input data tothe controller, the second sensor configured to detect and/or measure asecond temperature of the rail at a location of the rail that isaffected by temperature induced by the heating element; and softwarestored on the memory for executing the steps of: if the first input datacorresponding to the first temperature of the rail falls below a minimumthreshold temperature and if the second input data corresponding to thesecond temperature of the rail does not exceed a maximum thresholdtemperature, automatically cycling a flow of electricity on and off tothe heating element in accordance a pulse width modulated (PWM) cycle.